Sample App Error cudart.dll is not a valid windows image

I’m sorry if this is a newbie’s question,

But it seems that when I run any of the CUDA

samples, it pops up with the following:

The application ir DLL D:\CUDA\bin\cudart.dll is not a valid windows image. Please check this against your installation diskette.

I have Windows XP Pro 32 bit, the required CUDA Driver, and an 8800 GT.

I have tried reinstalling the CUDA toolkit many times.

I searched all I could, and couldn’t find an answer, please help.